Effective second line chemotherapy of advanced breast cancer with navelbine and mitomycin C

The efficacy and toxicity of navelbine 30 mg/m2 administered intravenously (IV) over 30 minutes every 3 weeks, and mitomycin C 15 mg/m2 administered IV every 6 weeks was assessed in 34 patients with metastatic breast cancer refractory to first-line chemotherapy. An overall objective response rate of 35% was achieved (95% confidence interval, 20% to 53%), with an additional 47% of patients maintaining stable disease (SD). Four of 12 patients who responded had received previous anthracycline therapy. Median time to progression for responders and patients with SD was 6.3 months. The median survival of all patients was 8.8 months. Tolerance of this regimen was remarkable. WHO grade 3/4 side effects consisted of granulocytopenia in 12% and thrombocytopenia in 15%, and included only 1 patient each with grade 3 neurotoxicity and local toxicity due to extravasation. Delay of treatment was required for hematologic toxicity in 7 patients, and 5 required dose reductions. In conclusion, navelbine/mitomycin C is an active and well-tolerated regimen that may be considered for second-line treatment. If our results are confirmed by larger analyses of other patients studies, this combination might also warrant further exploration in combination with other active agents for front line chemotherapy of advanced breast cancer.